This invention relates to means for converting flexible material to a relatively rigid state in a predetermined orientation and shape. In particular, this invention has application to pre-shaping automobile rooftop coverings made of vinyl, plastic, leather or the like.
Many automobiles are provided with partial or complete decorative rooftop coverings formed of sheet vinyl, plastic or the like. The covering material usually is a prefabricated flexible composite material comprising a relatively thin outer layer of decorative material and an inner layer of fiber material such as felt or the like which provides a cushioning effect and absorbs a suitable adhesive for permanently adhesively securing the rooftop covering to the smooth, rigid outer rooftop surface of an automobile.
Typically, the rooftop covering material is precut in a blank of approximately the proper size and shape for the particular application. Installation of this blank on the automobile rooftop is typically done on the automobile assembly line and is an extremely costly and time-consuming operation. Once the adhesive has been applied to the covering material and to the automobile rooftop, movement of the material on the rooftop is difficult and yet it must be done accurately and precisely and without damage to the material. In particular, a serious problem with grained vinyl materials is creasing of the material or contacting it in a way which would mar or obliterate the grain. Thus, a number of men must simultaneously work the material onto the automobile rooftop to insure proper positioning without wrinkling or creasing the material. Because of the difficult and time-consuming nature of the installation operation, the complete installation, including application of adhesive, fitting of the covering material on the rooftop and final trimming occupies 25 to 30 car lengths of expensive real estate on the final automobile assembly line, and can require the services of as many as 110 men. Even then, when the job is all done, the rooftop covering is susceptible to expansion or shrinkage of as much as one-quarter inch from exposure to temperature extremes of very hot and cold weather.